One of the great speeches of all time that every student in the United States should have read by high school graduation: 
George Washington's Farewell Address to the Nation

A speech every citizen should hear and study: "The Proper Role of Government" Ezra Taft Benson  

Or read it here: 
http://www.latterdayconservative.com/ezra-taft-benson/the-proper-role-of-government/
or here: 
http://www.zionsbest.com/proper_role.html

My favorite little video that every voter should watch: American Form of Government